WCXX

By putting a non-porous barrier between himself and Edna, Humphries has not only fed the idea of his character as someone else entirely, but also avoided having to do any talking on her behalf. So we're largely left with Edna's own explanation of what she means to us: "In the early days," she says, "I was mousy, timid, extremely reticent and, above all, vulnerable… then I grew in confidence and authority. I felt I had something to tell the audience, though I didn't know what it was. So I told them about themselves. I described my own home and people listened and they said, 'We know that house, we know that lava lamp, we know that picture on the wall, the Chinese girl with the tinted green face.' And slowly they began to feel that where they lived was not such a boring place, after all, because I had enshrined it in a work of art."

In other words, she represented a kind of universal dread; one that lurked in minds in places the young Humphries didn't even know existed: the fear of being left behind.

But where did the actual meat and bones of Edna come from? While Humphries is enduringly evasive on the subject, others have detected echoes of a troubled relationship with his mother. In his autobiography, My Life as Me, Louisa Humphries, wife of a Melbourne engineer, comes across as strident, fussy, narrow-minded and suspicious of anything that smacks of enlightenment. A particularly poignant passage recounts how young Barry, a voracious reader, returned home one day to discover that his mother had given all his books away.

"But why?" he sobbed. "They were my books."

"Don't be silly, Barry," sighed Mrs H. "You've read them."

While he doesn't pretend it was a particularly happy childhood, Humphries plays down the suggestion that he modelled Edna directly on Louisa – citing instead the family's talkative daily help, a local woman called Shores. "My poor mother has been press-ganged into the role of Edna's prototype," he has written, "by the speculations of critics. Naturally, the character has borrowed more than a little of my mother's astringency of phrase, but Edna's garrulity derives from Shores…"

Barry was never going to find his future in the Melbourne suburbs. From an early age he displayed a talent for repartee, putting together songs and sketches and displaying a fascination for surrealism and the Dadaist movement that drove much of his later work. While studying philosophy and fine arts at university, he penned a sketch about a woman offering accommodation to foreign athletes visiting Australia for the 1956 Olympics, "as long as they're white and speak English".

He hadn't intended to perform it himself, but when the female student due to play the part fell ill, Barry draped himself in a frock and took to the stage. In the decades that followed, he has been a restless perfectionist, moving between his homes in England, Australia, Switzerland and New York.

Despite 60 years as a performer, artist and writer, he remains an enigma behind those diamante-encrusted glasses. Even the women he has been married to have struggled to understand him. Brenda Wright, his second wife (of four), once said: "He puts a smokescreen around his personal life and presents himself in a certain way, which isn't reality. I was perturbed by the perceptions he had of people, some of which were very cruel."

It is better, and certainly Humphries's preference, to let Edna speak for herself. The threadbare dress and hairy legs have given way to resplendence, the company of notables, the homage of nations and the wisdom of age, but at heart the dame is still the gladdie-waving La Stupenda of Moonee Ponds.

"I always have to go back to Australia to reconnect with my roots," she explains. "Sitting under an anthill communicating with my spirit ancestors. That's how I get the strength I need to perform my mission, for that is what it is, possums: a glorious opportunity to pass on to ordinary people the gifts Dame Nature gave me."

Next year she will pass into retirement. And since we know that she's only human, we can't really complain.